@bene313 if you can paddle a 23 L board.... Ironman! I just got used (fitter) to surfing a 28 L board down from 33 L.
I ordered the 5'1" Vader last night, but living in Sydney I think the 5'2" might have been a better choice given the light winds we have here. I kite with 6 & 10 meter kites on a 5'10 surfboard currently which is probably 26 L. Kite use is suprisngly even between the two sizes as the southerly can often get +20 knots in winter.
Will let you know how it goes, but from what I've read it sounds like the board will be a bit loose in anything bigger than 4ft.